/Engine/Source/Runtime/InteractiveToolsFramework/Public/BaseGizmos/GizmoMath.h
Find the intersection of the ray defined by RayOrigin and RayDirection with the cone defined by ConeCenter, ConeDirection, ConeCosAngle, and ConeHeight. Where ConeCosAngle is the cosine of the cone opening angle, defined as the angle at the apex between the cone's axis and slant edge. Returns intersection success/failure in bOutIntersects and the hit depth parameter along the ray for the first intersection in OutHitDepth.
namespace GizmoMath { template<typename RealType> void GizmoMath::RayConeIntersection ( const FVector & ConeCenter, const FVector & ConeDirection, RealType ConeCosAngle, RealType ConeHeight, const FVector & RayOrigin, const FVector & RayDirection, bool & bIntersectsOut, RealType & OutHitDepth ) }